Lifting-jack.



N0 MODEL.

, PATENTED AUG. 30, 1904. H. J. SCHMIGK.

LIFTING JACK.

APPLIGATION FILED APR. 5, 1964.

2 SHEETS-SHEET 1.

PATENTED AUG. 30, 1904.

H. J. SGHMICK. LIFTING JACK. APPLICATION FILED APB. 5, 1904.

2 SHEETS-SHEET 2.

N0 MODEL.

Patented August 30, 1904.,

PATENT @Trice HENRY J. SCHMICK, OF HAMBURG, PENNSYLVANIA.

LlFTING-JACK,

SPECIFICATION forming part of Letters Patent No. r768,821, dated August 30, 1904, Application filed April 5, 1904. Serial No. 201,696. (No model.)

To @ZZ 1071/0771, 7115 mail concern:

Be it known that I, HENRY J. SCHMICK, a citizen of the United States, residing at Hamburg, in the county of Berks and State of Pennsylvania, have invented certain new and useful Improvements in Lifting-Jacks; and l do hereby declare the following' to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to lifting-jacks, and has for its object the application of a high degree of power without sacrificing time and 'sustaining the weig'ht of the article being' raised without the use of additional or extraneous mechanism; and the invention consists in certain improvements in construction, which will be fully disclosed in the following specification and claims.

In the accompanying' drawings, which form partof this specification, Figure 1 represents a by bolts and provided with-a shaft-bearing.

T helifting-bar 7 is provided with a head'8, a toe-piece 9, which projects through the slot 3,

and with toothed racks 10 1() on-opposite sides of its transverse center.

11 indicates a gear-wheel having radial teeth 12 and pinions 173 13, which engag'e the racks 10'10 on the lifting-bar 7 to raise and lower the bar, and is mounted in bearings 15 15 on opposite sides of the body 1 and secured in position by a cotter-pin 16.

1V ithin the hood or cover 4 is a revoluble disk or head 17 at a right ang'le to the wheel 11 and on whose inner face is a radio-helical member 18, and to effect constant engagement of thc working surface 19 of said member with the teeth 12 said surface 19 is made angular in transverse section of the member and of a constantly-increasing angle from the root or point of engagement 2O with a tooth, and the inner surface 21 of said member is inclined in the same ratio, butin reverse direction, to prevent binding of the neXt tooth thereon as the disk revolves. This increasing incline or angularity of the member 18 causes the member to support the weig'ht on the jack at any point in the travel of the lifting-bar 7 by engagement of the teeth 12 of the wheel therewith and dispenses with the use of a ratchet and pawl for the purpose. The member 18 in the present instance has overlapping ends, with a space 22 between the ends for the passage of teeth 12, and two of said teeth are in constant engagement with the member 18, and in the revolution of the disk 17 all the teeth 12 are eng'aged consecutively. The disk 17 is provided with a shaft 23, supported in a bearing 24 on the cover 4, and on said shaft is secured a ratchet 25 of any preferred construction for revolving the disk and raising and lowering the lifting-bar 7.

Having thus fully described my invention, what I claim.is-

1. A lifting-jack having a revoluble disk provided with a working member on the face thereof, having a working surface of constantly-increasing' angularity from the root of the member outward, and a power-shaft supported in the casing of the jack; in combination with a revoluble member having peripheral teeth engaged by said working member, pinions on the sides of the revoluble member and supported in said casing, and a vertically-movable member provided with toothed racks engaged by said pinions.

2. Aylifting-jack having' a revoluble disk provided with a shaft, anda helical working' member on the face thereof, having a working surface of constantly-increasing angularity from the root of the member outward, a detachable cover inclosing said disk and supporting the shaft thereof; in combination with a revoluble member having peripheral teeth engaged by said working member, pinions on the sides of the revoluble member, a shaft on which said member and pinions are mounted, and a vertically-movable member provided with toothed reeks engaged by Saud pinlons. l l l on the sides thereof, a shaft for Said member supported in the easing of the jack, and a vertically movable member provided with toothed reeks engaged by Said pinions.

In testimony whereof I aiiix my signature in presence of two witnesses.

HENRY J. SCHMICK.

Witnesses:

ADAM BoDENl-IORN, J. ED. MILLER. 

